That's a good question and I wish I knew the answer. My first inclination is to say, "I doubt it", but it's really hard to say.

It's important to know that mercury makes it way into our lives from many other sources as well. Here's a partial list (overview taken from It's All In Your Head by Dr. Hal Huggins ):

Certain Seafoods
Cosmetics
Antiseptics
Psoriasis Preparations
Fungicides
Ance Preparations
Bleaching Creams
Eye & Ear & Nasal Preparations
Throat Lozenges
Hemorrhoidal Ointments
Vaginal Jellies/Tables/Douches
Hair Tonics
Veterinary Preparations
Prophylactic Kits
Household chemicals like mildew resistant paints
Garden Chemicals
Turf Fungicides and Disinfectants
Plant Fungicides
Herbicides
Insecticides
Misc... Adhesives, fabric softeners, Air conditioner filters, felts, floor waxes and polishes, tattoos, chlorine production, artificial silk manufacturing, embalming, electroplating, explosives production, fingerprint detection, mirror production, neon light manufacturing, textile printing, and many more.

Since this book was written, some of the categories above may have been eliminated by changes in law.